Your average sitcom doesn't have many big mysteries. But Community has never been much of an average sitcom. Thus, the beloved NBC comedy has had a big mystery for quite awhile: Who is Jeff Winger's father?

Thanks to a photo posted by Joel McHale on Twitter, we may know who is playing Jeff's dad in Community season 4. So who is it?

On Tuesday, September 18, Joel McHale, the actor who plays Jeff Winger on Community, posted a photo on Twitter. The caption read:

"On set at #Community with the great, terrific, & cool #JamesBrolin."

And the speculation began.

Why would anybody think that James Brolin has the job of the elder Winger?

1. Joel McHale did not specify any sort of role for James Brolin, leading us to believe that it's a secret.

2. NBC has not announced James Brolin as a Community season 4 guest star. Considering the prominence and fame of the actor, this makes no sense unless he is playing an important, surprise role.

3. Anonymous sources confirmed to another website, TVLine, that Brolin was indeed at Community to play the dad.

4. All signs point to Jeff's dad appearing this season.

James Brolin is an Emmy-winning actor (for Marcus Welby, M.D. in 1970) who has appeared on television and in films since the early 1960s. In addition to his role on Marcus Welby, Brolin was a regular on TV shows like Hotel, Pensacola: Wings of Gold and has appeared more recently in The West Wing, Monk and Psych.

Will James Brolin indeed play the father of Jeff Winger? What other part could he play on Community? Is this the kind of actor you wanted for the role, or were you thinking of somebody else? Do you think we should even meet Jeff's dad at all? Leave your comments below!